MT4: closing orders manually vs script

Can someone offer an explanation as to why I sometimes get errors (like 146) when using a "close all orders" script yet if I immediately try to close the orders manually there's no problem.

The script is not at fault, it's a well known script called "close-all-orders.mq4" which may be familiar to many, the issue seems to be related to how MT4 handles manual closures as opposed to those initiated by a script.

I'm not familiar with the internal workings of MT4 and would like to understand exactly what's going on here, so any help would be appreciated...

Error 146 is trade context busy which means that the MT4 trading thread on your machine is performing another trade operation. This problem would only come up in scripts or EAs which try to do too much to soon. The MT4 terminal has code to prevent from happening - in other words you can't close another order if the previous one is still being handled. EAs and scripts can avoid this error by using the IsTradeContextBusy() and Wait() functions. If you are not up to coding, just run the script repeatedly until all orders are closed.

You can't assume that because a script is well known and widely used that it was written properly or that you have the latest version.

Thank you for your advice, but I'm fully versed in everything from assembly to C++ (I put MQL somewhere in the middle) and I know what I'm doing in that regard. I've looked at the code in the script and I know exactly what it does.

My post clearly wasn't detailed enough so let me clarify. This is not an issue with the script I'm using, it's an internal issue within MT4 which happens *sometimes*, not every time. For example:

1) I open a few positions.

2) I apply the "close all" script.

3) Given that the MT4 terminal is not doing anything else at this time it should close all orders unless, as you said, the trade context is busy.

4) Nothing happens, I assume trade context is busy.

5) I try to close one order manually - it closes immediately.

6) I wait for the script to close the remaining orders - I know the trade context is not busy as I've just closed an order, but nothing happens.

7) I manually close another order - it closes immediately.

8) I wait for the script to close the rest - still nothing happens.

Now this has happened many times and I'd like to know why I can close orders manually when the script can't, it's not a trade context issue.

I had the same thing happen in live trading on Mt4 and I have no explanation for it.

Sometimes I thought that maybe the script had just stopped although there were still open orders, but I am not sure.
Closing the orders manually worked as you described it.

But sometimes even closing them manually did not work because
I got the "trade context is busy" message and then
only shutting down Mt4 and restarting it cleared the way to
close the open orders.